It comes into play when you're travelling from one of the upper stations of the Northern line down to the south, or vice versa, and involves switching to the Victoria line between Euston and Stockwell, for a swifter journey through the central zone — then hopping back onto the Northern line to your final destination.

You might wonder whether this is really a worthwhile shortcut. If you look at a street map, you'll see that both the Victoria line and Northern line take pretty direct routes from Euston to Stockwell: the distance travelled underground is almost exactly the same length for both lines, at approximately 7.5km (that's assuming you’re on the Charing Cross branch: the City branch, with its detour to the east, travels just under 10.5km.)

The secret is that there are fewer stops on the Victoria line – it calls at seven stations, versus 10 or 11 on the Northern line. What's more, those stations benefit from 'humped' tracks, which help the trains decelerate into the platform, and accelerate away, more rapidly. As a result, Victoria line trains cover much more of the distance at 'cruising speed' than their Northern line counterparts.

The TfL timetable reveals the scale of the advantage. It takes just 12 minutes to get from Euston to Stockwell on the Victoria line, versus 17 minutes on the Northern line via Charing Cross, and 22 minutes if you go via Bank. And because the Victoria line largely sidesteps the West End, there's less chance of a crush at busy times.

The potential time savings

For certain routes, the Victoria line cut can make a big difference.

Let's take an imaginary journey from Hampstead to Balham. On a weekday afternoon, the average interval between southbound trains at Hampstead is three minutes, so you can expect to be waiting for 90 seconds on average before stepping onto a train. It's evens whether that train will be travelling via Bank or Charing Cross; for now, let's assume it’s going via Bank. According to the timetable, that means you’re looking at a 38-minute ride to Balham. Add in your wait at the platform and that’s a total journey time of 39½ minutes.

The Victoria line cut can slash that.

Your Bank branch train will pull into Euston nine minutes after you board, and if you hop off there you’ll find the southbound Victoria line platform directly across the concourse.

Victoria line trains run from this platform roughly every two minutes for most of the day, so you should only be waiting for a minute or so. As mentioned above, the journey time from here to Stockwell is 12 minutes – and once you get there, the Victoria and Northern line platforms are once again directly adjacent.

So now you just need to wait for another Northern line to get you to Balham. Once again, the average wait is 1½ minutes, and once you're on board it takes seven minutes to get to Balham. Your total journey time works out to 1½ minutes (waiting) + 9 minutes (to Euston) + 1 minute (waiting) + 12 minutes (to Stockwell) + 1½ minutes (waiting) + 7 minutes (to Balham) = 32 minutes. Congratulations — you've reduced your journey time by nearly 20%.

Charing Cross complications

What if the first train you board at Hampstead is going via Charing Cross? In that case, things aren’t quite so simple. For a start, most Charing Cross trains terminate at Kennington — only during peak times do a few services go all the way to Morden. Riding all the way through to Balham normally isn't even an option.

Can you once again beat the timetable by changing at Euston? Alas, in this case probably not. When you arrive at Euston on a Charing Cross branch train, you'll find yourself over on the opposite side of the station to the Victoria line. Instead of a mere hop across the concourse, you're faced with a moderate walk involving two escalators. Getting from one platform to the other took us nearly three minutes at a brisk commuter pace, entirely wiping out the advantage of changing lines.

If you're really desperate to get to Balham in the fastest time possible, there is one other option open to Charing Cross branch passengers: stay on the Northern line for an extra stop and switch to the Victoria line at Warren Street. The change still involves two escalators, but the walk is shorter. We did it in just under two minutes, so it could well shave a minute or so off your journey.

Without a doubt, things are easier on the Bank branch. But if a Charing Cross service comes along first, you might as well get on it, rather than holding out for the next Bank train. Since Northern line services are timetabled at three-minute intervals, the extra wait will cancel out the benefit of the faster journey.

Going the other way

What if you're travelling the other way — from Balham up to Hampstead? Here an additional variable arises. When you're standing on the platform at Balham, the first train to arrive might well be going to High Barnet, rather than heading up the Edgware line via Hampstead.

To the savvy traveller, however, this extra complication is a red herring. Since Balham is south of Kennington, pretty much every train that comes through will be going up the Bank branch. If you were to go all the way to Hampstead on one of these trains, you'd be looking at an average of 3 minutes (waiting) + 38 minutes (to Hampstead) = a tiresome 41-minute journey.

You can do a bit better by catching the first train that arrives at Balham — regardless of its eventual destination — then changing at Kennington for the Charing Cross branch of the Northern line. You'll have to factor in waiting time, however, since again every other service will be going to High Barnet. You can expect a total journey time of 1½ minutes (waiting) + 12 minutes (to Kennington) + 3 minutes (waiting) + 22 minutes (to Hampstead) = 39½ minutes. It's faster than staying on the Bank branch, but not by much.

Once again, the Victoria line cut comes up trumps. Take the first Northern line train from Balham and you'll be at Stockwell seven minutes later. From there, Victoria Line trains run every three minutes, and will whizz you up to Euston in a brisk 12 minutes.

Once you reach Euston, switching back to the Northern line is a simple matter of sauntering across the concourse. At this point you might have to exercise a little patience: Euston as a whole is served by one northbound Northern line train every 1½ minutes, but only Bank branch trains come to this platform, and only half of those will be going to Edgware, so on average you’ll have to wait three minutes for a suitable service.

The last word

For the sake of simplicity, we've based our calculations on a typical weekday journey. There are certainly other variables that might affect your choices, such as if you want to go to Mill Hill East, or to travel late at night when the average wait for a train is longer.

All the same, the principle holds for the vast majority of cross-town journeys. And if, understandably, you can’t carry all the details around in your head, the good news is that can be boiled down to a very simple flowchart:

Since the great majority of tube journeys either start or end in zone 1, the Victoria line cut probably won’t be useful to you every day. But if you use it just once in your life then the few minutes you've just spent reading this guide will have been worth it.

Interestingly the provision of cross platform interchanges when the Victoria Line was built was brought up by Lord Adonis recently when he recalled how when he was in charge of the Crossrail project in the last Labour government he was concerned about the long interchanges passengers would have with the plans for Crossrail . However, as labour lost the following election he could do nothing and in fact nothing was done with interchanges.

Imagine if it had been planned to build Crossrail tunnels either side of the central line with similar cross platform interchanges using new central line platforms on opposite side of trains in place of the present restricted central platforms with Central Line and Crossrail sharing same escalators and lifts!

It will be interesting to see if Lord Adonis can develop better interchanges for Crossrail 2 now he is chairman of this project.

Padmadipa

There are a number of short cuts using the Victoria line - my favourite is if one is trying to get to Waterloo from the upper reaches of the Piccadilly line - the usual way it is done is by coming all the way down the Piccadilly and changing at Leicester Square onto the Northern. My short cut is to alternatively change onto the Victoria at Finsbury Park (cross platform interchange) and then change again onto the Bakerloo at Oxford Circus (again cross platform interchange). This is quite counter-intuitive as it looks like by traveling to Oxford Circus you are going out of your way. But from timings that I have done it will shave at a minimum 5 minutes and probably more than using the Leicester Square route!

TheDanielCoyle .

When heading north from Euston get the first northbound tain wherever it's going to, and if you're in the last carriage it's a quick and normally quiet transfer at Camden to the High Barnet/Edgware branch. You can then often pick up the train from the Charing Cross branch. If not you'll still have time to get the train from Bank you would have got at Euston

Clive Road

Don't do this going south after 4/5 pm on a weekday . Gains are wiped out by platform congestion at Stockwell more often than not

Egg

Just a little error in this article. It says that changing from the Northern via CX to Victoria line at Euston is a "moderate walk with two sets of escalators". It is in fact a moderate walk up one set of stairs and down one set of escalators.

Philip Day

I have 3 kids a pushchair and some baggage. I’ll sit tight thanks.

Andrew

My advice is, if you can get a seat at Hampstead, stay on it as far as you can go.....